Devices known as __________ often serve as the brains of an automated machine.

The term that describes the devices which act as the brains of an automated machine is "controllers." Controllers are responsible for processing input data from various sensors, making decisions based on that data, and then sending appropriate commands to actuators to perform specific operations. They are critical for the functioning of automation systems as they ensure that processes are carried out smoothly and efficiently based on real-time data.

In contrast, relays are electromechanical switches that control the opening and closing of circuits but do not process data or make decisions. Sensors are devices that gather information from the environment, such as temperature or pressure, but they do not interpret this data. Actuators are responsible for carrying out physical actions as directed by controllers but lack the capability to process information. Each of these components plays an important role in automation, but the controller specifically fulfills the function of integrating data processing and control logic.